JFBComment + Jomsocial?

Yes, absolutely. To put it on JomSocial pages, there are 2 options:
1) Use the JFBCComments module. With this, you can place the Comments block in a module position that would show up on the page. If you leave the URL parameter in the module blank, the comments will be for whatever page the module is shown on (good for using across multiple pages).
2) Use the {JFBCComments} tag. For this, you'd need to actually edit the JomSocial template file for whatever page you're looking at. Then, in that template, simply add {JFBCComments}. There are additional parameters you can add to the Comments tag that can be seen on the configuration guide page below:
www.sourcecoast.com/jfbconnect/docs/conf...ation-guide?start=13

Hope that helps, but if you have any specific questions, just let us know!